package ooday01;

public class ConsDemo {
    public static void main(String[] args) {
        Student zs=new Student();
        Student ls=new Student("李四",25);
        Student ww=new Student("李四",25,"jsd2302","001");

        zs.sayHi();
        ls.sayHi();
        ww.sayHi();


    }
}
